B-STOCK. This is a product which has been returned by a customer within their 14-day money-back guarantee or opened by our team to test. Fully functional and come with a full warranty. --Compatibility with systems: IOS/Android/Windows Device control through a dedicated application and connection to a 2.4GHz WI-FI network Number of LEDs in the arm: 256 Resolution: 512 x 512 Display brightness: 800cd/m².